High-performance aluminum profile for battery tray and preparation method of high-performance aluminum profile

Abstract

According to the high-performance aluminum profile for the battery tray and the preparation method of the high-performance aluminum profile, after components are optimized, the content of main alloy elements is controlled within a specific optimization interval, the high strength and the extrudability of the aluminum profile are guaranteed, the content of strengthening phase Mg2Si and a proper amount of excessive Si and Cu are controlled, and therefore the strength of the aluminum profile is improved. Under the condition that quenching sensitivity and deformation resistance are not excessively increased, the tensile strength of the profile is improved to 419 MPa or above, the yield strength reaches 359 MPa or above, meanwhile, the percentage elongation after fracture is kept 13.6% or above, and the requirements of the battery tray for high strength and high toughness of materials are met. Besides, the process is optimized, composition segregation and dendritic crystal networks of as-cast structures are effectively eliminated, deformation is more uniform, the risks of defects such as surface cracks and dragging breakage are greatly reduced when the complex-section profile is extruded, and therefore the extrusion formability and the product yield are remarkably improved, high operability and repeatability are achieved, and the method is suitable for large-scale popularization and application. The stable and efficient large-scale industrial production is facilitated.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy preparation technology, and more specifically, to a high-performance aluminum profile for battery trays and its preparation method. Background Technology

[0002] Aluminum alloys are widely used in the automotive industry due to their lightweight, high specific strength, and good corrosion resistance. With the rapid development of new energy vehicles, battery trays, as key structural components, have placed higher demands on the mechanical properties, corrosion resistance, and machinability of materials.

[0003] Traditionally, high-strength 2XXX series (such as 2024, Al-Cu-Mg series) and 7XXX series (such as 7075, Al-Zn-Mg-Cu series) aluminum alloys have dominated the aerospace structural materials field. 2XXX series alloys possess good damage tolerance and fatigue performance, while 7XXX series alloys have the highest specific strength. However, both types of alloys share a significant drawback: poor corrosion resistance, particularly resistance to stress corrosion cracking (SCC), which limits their application in certain harsh environments and increases maintenance costs. 6XXX series (Al-Mg-Si series) alloys are favored by automotive customers for their excellent corrosion resistance, formability, and weldability. However, with the continuous upgrading of automotive battery trays, the requirements for material mechanical properties are constantly increasing, and the currently widely used medium-strength alloys such as 6061 and 6082 can no longer meet customer requirements. Against this backdrop, a new type of 6-series aluminum alloy suitable for the complex cavity profiles of battery trays is needed as an improvement and supplement to traditional high-strength aluminum alloys, achieving a good balance between strength, corrosion resistance, and weldability. The application of 6-series aluminum alloy profiles in the automotive battery tray field still faces some challenges: 1. To achieve high strength, the profiles are often highly alloyed, resulting in poor extrudability. Furthermore, the complex cross-section of battery tray profiles makes them prone to surface defects and unstable dimensional accuracy during extrusion. 2. Quenching control is difficult: to achieve high strength, online quenching at high temperatures is required. However, excessively high outlet temperatures can lead to profile deformation, decreased surface quality, and even "drag-and-burn" defects, affecting the yield. 3. Poor microstructure uniformity: The ingot contains compositional segregation and non-equilibrium eutectic structures, affecting subsequent processing performance and final mechanical properties.

[0004] Therefore, there is an urgent need to develop a high-performance 6-series aluminum alloy profile suitable for battery trays and its preparation method to solve the above-mentioned technical problems and meet the automotive industry's increasing demand for comprehensive material performance. Summary of the Invention

[0005] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides a high-performance aluminum profile for battery trays and a method for preparing the same, the specific technical solution of which is as follows: The high-performance aluminum profile for battery tray comprises the following components in mass percentage: Mg 1-1.1%, Si 0.8-0.9%, Mn 0.25-0.30%, Cu 0.7-0.8%, Fe not more than 0.15%, and the balance of Al; the content of each impurity element is not more than 0.05%, and the total content of impurity elements is not more than 0.15%.

[0006] Further, the high-performance aluminum profile for battery tray has a tensile strength of ≥419 MPa, a yield strength of ≥359 MPa, and an elongation after fracture of ≥13.6%.

[0007] In addition, the application also provides a preparation method of the high-performance aluminum profile for battery tray, which comprises the following steps: S1. Melting and casting: adding high-purity aluminum ingots, silicon and manganese additives into a melting furnace, heating until melting, then adding magnesium ingots, melting, and fully stirring the melt after the charge is completely melted; S2. In-furnace refining and refining treatment: adding a refining agent for refining treatment, stirring fully, then skimming the slag, and after standing for 20-30 min, adding a refining agent after confirming that the components are within the designed range; S3. Casting: using a semi-continuous horizontal hot top casting method for ingot casting, the aluminum melt enters the crystallizer through a guide plate, the lowering speed of the lifting platform is controlled according to the flow rates of the melt and the cooling water, and the aluminum bar is gradually formed during the lowering process; S4. Online detection: the aluminum bar is detected by a macro sample, and after meeting the requirements, it enters the homogenization treatment process; S5. Extrusion and online quenching: heating the aluminum bar after homogenization treatment to 500-520°C within 3-5 min, the extrusion temperature of the aluminum bar is 500-520°C, the mold temperature is 470-490°C, the extrusion cylinder temperature is 400-450°C, the extrusion speed is 1.5-2.5 mm / s, the profile discharge temperature is 530-550°C, and online quenching treatment is performed to cool the profile to below 50°C within 1 min; S6. Artificial aging: aging the extruded profile at 170-190°C for 7-9 h.

[0008] Further, in step S1, the melting temperature is 730-760°C.

[0009] Further, in step S2, the refining treatment is performed by using a composite rotary blowing process, first blowing a mixed gas of argon and chlorine for 10-15 min, then adding a refining agent, and continuing the refining treatment for 15-20 min, the hydrogen content of the melt after refining is ≤0.10 mL / 100 g Al, and the inclusion content is ≤5 pieces / mm.

[0010] Further, the refining agent is obtained by mixing sodium chloride and graphite in a mass ratio of (1-5):(5-9). The adding amount of the refining agent accounts for 0.1-0.3% of the melt mass.

[0011] Further, the refining agent is Al-5Ti-1B wire; the adding amount of the refining agent accounts for 0.02-0.03% of the melt mass.

[0012] Further, in step S3, the temperature for casting is 710-720℃, the casting speed is 90-100 mm / min; the cooling water pressure is 0.1-0.2 MPa, and the cooling water temperature is ≤50℃.

[0013] Further, in step S4, the temperature for homogenization treatment is 560-580℃, and the holding time is 8-9h.

[0014] In addition, the application also provides a battery tray prepared from the high-performance aluminum profile.

[0015] Compared with the prior art, the application has the following beneficial effects: 1. After optimizing the components, the content of the main alloying elements Mg, Si, Cu and Mn is controlled in a specific optimization range, so that the alloy significantly improves the extrudability under the premise of ensuring high strength. Specifically, by controlling the content of the strengthening phase Mg2Si, appropriate excess Si and suitable Cu, the tensile strength of the profile is increased to more than 419MPa, the yield strength is increased to more than 359MPa, and the elongation after fracture is maintained at more than 13.6%, which meets the demand of the new generation of battery trays for high strength and high toughness materials.

[0016] 2. By adding Mn element, the harmful coarse β-AlFeSi phase is converted into fine α-AlFeMnSi phase, and combined with strict ingot homogenization treatment (560℃ / 9h), the composition segregation and dendritic network of the as-cast structure are effectively eliminated, so that the deformation of the alloy is more uniform, which is beneficial to increase the mechanical strength of the profile.

[0017] 3. By controlling the extrusion process parameters, the solid solution of the strengthening phase Mg2Si is ensured, which lays a foundation for subsequent aging strengthening, effectively avoids the problems of profile deformation and size out-of-tolerance caused by excessive temperature or uneven cooling, so that high performance is obtained while the excellent size precision and surface quality of the profile are ensured.

[0018] 4. Through the optimization control of the components, component proportioning and process, the performance of the profile can be balanced as a whole, the process flow parameters are clear and accurate, the compatibility with the existing aluminum processing industry equipment is good, the high operability and repeatability are possessed, the stable and efficient large-scale industrial production is beneficial, and the profile is applied to the preparation of the battery tray, and the application requirement of the battery tray is met.

[0019] 5. Through the online quenching treatment, the flow of the gas and the mist water is accurately controlled, the temperature of each part of the profile can be more accurately balanced, the process is more stable, the quenching deformation is reduced, and the consistency of the profile is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a metallographic structure schematic diagram of the profile prepared in embodiment 1 of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is further described in detail in combination with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and do not limit the protection scope of the present application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0023] The high-performance aluminum profile for the battery tray in an embodiment of the present application comprises the following components in mass percentage: Mg 1-1.1%, Si 0.8-0.9%, Mn 0.25-0.30%, Cu 0.7-0.8%, Fe not more than 0.15%, and the balance of Al; the content of each impurity element is not more than 0.05%, and the total content of the impurity elements is not more than 0.15%.

[0024] In the present application, in order to ensure the strength of the alloy, the contents of Mg2Si and excess silicon in the Al-Mg-Si alloy are controlled. The main strengthening phase of the alloy is Mg2Si. The tensile strength of the alloy increases with the increase of the contents of Mg2Si and excess silicon, but at the same time, the quench sensitivity of the alloy also increases, the elongation and the extrudability decrease, thereby increasing the difficulty of extrusion production. The average content of the strengthening phase Mg2Si in the alloy is controlled to be less than 1.0%, and the average content of the excess silicon is controlled to be not more than 0.35%. The alloy contains Fe and Mn, and in the actual casting crystallization process, the Si in the alloy will preferentially form β-AlFeSi or α-Al 12 (Fe Mn)3Si intermetallic compound, so part of the Si is consumed, therefore, the content of Mg in the alloy is controlled to be 1.0-1.1%, and the content of Si is controlled to be 0.8-0.9%. The most significant role of Mn in the 6 series alloy is to refine the grains, and the appropriate amount of Mn can inhibit the grain coarsening in the ingot homogenization process, form a fine equiaxed grain structure, and reduce the quench sensitivity. The Mn element can convert the coarse β-AlFeSi phase formed by the impurity Fe into a fine α-AlFeMnSi phase, therefore, 0.25-0.30% of Mn is added to optimize the structure. The addition of Cu in the alloy can play a certain solid solution strengthening effect, and the two main strengthening phases formed by Cu are θ (CuAl2) and S (Al2CuMg) phases. The transus strengthening effect of the S phase in the alloy is the best, the transus strengthening effect of the θ phase is slightly less, and when the transus phases S and θ exist in the alloy at the same time, the strengthening effect is the largest. Therefore, the content of Cu is controlled to be 0.7-0.8%, which can achieve high strength while maintaining good corrosion resistance. The content of impurity Fe is strictly controlled, and too high Fe content will form coarse β-AlFeSi phase, which has a great influence on the corrosion resistance, fatigue performance and extrusion performance of the alloy, and the content of Fe is strictly controlled to be less than 0.15%.

[0025] In one embodiment, the high-performance aluminum profile for battery trays has a tensile strength ≥ 419 MPa, a yield strength ≥ 359 MPa, and an elongation after fracture ≥ 13.6%.

[0026] In addition, the present application also provides a preparation method of the high-performance aluminum profile for battery trays, which comprises the following steps: S1. Melting and casting: adding high-purity aluminum ingot, silicon and manganese additives into a melting furnace, heating until melted, then adding magnesium ingot, melting, and fully stirring the melt after the furnace charge is completely melted; S2. In-furnace refining and refining treatment: adding a refining agent for refining treatment, fully stirring and then skimming the slag, and after standing for 20-30 min, adding a refining agent after confirming that the composition is within the designed range, and casting the aluminum melt; S3, casting: the ingot is cast by a semi-continuous horizontal hot top casting method, the aluminum melt enters the crystallizer through the guide-in disc, the descending speed of the lifting platform is controlled according to the flow rates of the melt and the cooling water, and the aluminum bar is gradually formed in the descending process; S4, on-line detection: the aluminum bar is detected by a macro sample, and after meeting the requirements, the aluminum bar enters a homogenization treatment process; S5, extrusion and on-line quenching: the aluminum bar after the homogenization treatment is heated to 500-520 DEG C within 3-5 min, the extrusion temperature of the aluminum bar is 500-520 DEG C, the die temperature is 470-490 DEG C, the extrusion cylinder temperature is 400-450 DEG C, the extrusion speed is 1.5-2.5 mm / s, the profile discharge port temperature is 530-550 DEG C, and on-line quenching treatment is carried out, so that the profile is cooled to below 50 DEG C within 1 min; S6, artificial aging: the profile after the extrusion is aged at 170-190 DEG C for 7-9 h.

[0027] In one of the embodiments, in step S1, the smelting temperature is 730-760 DEG C.

[0028] In one of the embodiments, in step S2, the refining treatment is carried out by using a composite rotary blowing process, first, a mixed gas of argon and chlorine is introduced for 10-15 min, then a refining agent is added, and the refining treatment is continued for 15-20 min, after the refining, the hydrogen content of the melt is ≤0.10 mL / 100 g Al, and the inclusion content is ≤5 pieces / mm.

[0029] In one of the embodiments, the refining agent is obtained by mixing sodium chloride and graphite in a mass ratio of (1-5):(5-9). The adding amount of the refining agent accounts for 0.1-0.3% of the mass of the melt.

[0030] In one of the embodiments, the refiner is Al-5Ti-1B wire; the adding amount of the refiner accounts for 0.02-0.03% of the mass of the melt. Ti in the alloy has the effects of refining the casting structure and the weld structure and reducing the cracking tendency. The on-line casting of Al-5Ti-1B can achieve a good grain refinement effect. Therefore, the adding amount of the refiner is controlled to be 0.02-0.03%. Since Ti and B are added in the form of an auxiliary agent, the profile also contains the components of Ti and B, which can exist in the form of impurities, and details are not described herein.

[0031] In one of the embodiments, in step S3, the casting temperature is 710-720 DEG C, the casting speed is 90-100 mm / min, the cooling water pressure is 0.1-0.2 MPa, and the cooling water temperature is ≤50 DEG C.

[0032] The casting temperature in the present application is selected to ensure that the alloy melt has good flowability during casting, and only good flowability can ensure good mold filling property of the alloy melt. Factors affecting the casting temperature include the flow distance of the molten aluminum (length of the flow channel), temperature drop during flow (length of the flow channel and ambient temperature), alloy composition, ingot size, and melt flow rate in the flow channel. The casting temperature should be 50-100℃ higher than the liquidus temperature of the alloy. In addition, since the diameter of the cast alloy ingot is large, the solidification speed of the inner and outer parts of the ingot is not uniform during casting, and porosity defects are easily produced. If the casting temperature is too low, the center part of the ingot cannot be effectively and timely fed, and serious porosity defects can be produced, thereby causing cracks in the extruded product during subsequent extrusion, and seriously affecting the quality of the extruded product. The casting temperature in the present application is 710-720℃. Since a graphite sleeve is embedded in the hot top casting crystallizer, it plays a cooling and lubricating role during cooling. The width of the graphite sleeve is determined, and therefore the cooling height of the ingot is fixed. The casting speed should be selected to ensure that the alloy ingot has good formability, that is, to ensure that the alloy ingot does not have cracks and has good surface quality. The casting speed in the present application is 90-100 mm / min. Cooling intensity has a great influence on the ingot structure, performance, cracking tendency, and surface quality of the ingot. The flow rate, flow speed, and temperature of the cooling water, the structure of the crystallizer, and the casting temperature are three basic factors determining the cooling intensity. In industrial aluminum alloy melting and casting production, for a given alloy grade and ingot size, the structure of the crystallizer and the casting temperature are basically fixed, and the cooling intensity of the ingot can only be controlled by adjusting the flow rate and flow speed of the cooling water. In order to obtain a profile with better performance, the cooling water pressure in the present application is 0.1-0.2 MPa.

[0033] In one embodiment, in step S4, the grain size of the aluminum bar is 1-1.5 levels (1.5 level only in the center part of the ingot); the porosity is less than 1 level; no slag inclusion and crack defects are found in the macrostructure, and no bright crystal and feather-like grain structure is found; no slag inclusion, obvious scratches, and cold shut defects are found in the appearance of the ingot; and no internal cracking is found by ultrasonic flaw detection.

[0034] In one embodiment, in step S4, the temperature of the homogenization treatment is 560-580℃, and the holding time is 8-9h. During semi-continuous casting, rapid cooling can cause unevenness of the ingot structure and composition, and the ingot can remain uneven stress, and after homogenization treatment, the structure is uniform, and segregation and coarse dendrites are basically eliminated.

[0035] In one of the embodiments, in step S5, the on-line quenching treatment adopts a gas-mist-water on-line quenching system, which first pre-cools the profile by passing in gas, and then dynamically adjusts the flow of gas-mist-water according to the information fed back by real-time infrared thermal imaging, and precisely cools different regions of the profile.

[0036] In one of the embodiments, the temperature of the gas in pre-cooling is -5℃-20℃.

[0037] In one of the embodiments, the temperature of the mist and water is 15℃-35℃.

[0038] In addition, the application also provides a battery tray, which is prepared from the high-performance aluminum profile.

[0039] The embodiments of the application will be described in detail below with specific examples.

[0040] Examples 1-3: The chemical composition and component ratio of the high-performance aluminum profile for battery tray in Examples 1-3 are shown in Table 1. The preparation method of the high-performance aluminum profile for battery tray in Examples 1-3 comprises the following steps: S1. Melting and casting: add high-purity aluminum ingot, silicon and manganese additives into a melting furnace, heat until melted, then add magnesium ingot, melt at 760℃, and fully stir the melt after melting of the furnace charge; S2. In-furnace refining and refining treatment: the refining treatment adopts a composite rotary blowing process, first pass in a mixed gas of argon and chlorine for 15min, then add 0.3% of refining agent (obtained by mixing sodium chloride and graphite with a mass ratio of 5:5) based on the mass of the melt, continue refining treatment for 20min, the hydrogen content of the melt after refining is ≤0.10mL / 100gAl, the inclusion content is ≤5 / mm, after fully stirring, remove the slag, after standing for 30min, add 0.02% of Al-5Ti-1B wire based on the mass of the melt after confirming that the composition is within the designed range; S3. Casting: the ingot is cast by a semi-continuous horizontal hot top casting method, the aluminum melt enters the crystallizer through the guide plate, the lowering speed of the lifting platform is controlled according to the flow rate of the melt and cooling water, and the aluminum bar is gradually formed during the lowering process. The temperature of casting is 720℃, the casting speed is 95mm / min; the cooling water pressure is 0.1-0.2 MPa, and the cooling water temperature is ≤50℃; S4. Online detection: the aluminum bar is subjected to performance test, and after meeting the requirements, the aluminum bar is subjected to homogenization treatment process, and the temperature of the homogenization treatment process is 560℃, and the holding time is 9h; S5. Extrusion and online quenching: the aluminum bar after the homogenization treatment is heated to 500℃ within 5min, the extrusion temperature of the aluminum bar is 520℃, the die temperature is 480℃, the extrusion cylinder temperature is 420℃, the extrusion speed is 2.2mm / s, the profile discharge port temperature is 540℃, and then the profile is pre-cooled by passing in a gas with a temperature of 10℃, and then according to the information fed back by the real-time infrared thermal imaging, the flow of gas-mist-water is dynamically adjusted, when the mist and water are passed in, the temperature of the mist and water is controlled to be 25℃, the profile is accurately cooled in different regions, and the profile is cooled to below 50℃ within 1min; S6. Artificial aging: the profile after the extrusion is subjected to aging treatment at 175℃ for 8h.

[0041] Comparative Examples 1-5: Comparative Examples 1-5 are different from Example 1 in that the composition and the composition content of the profile of Comparative Examples 1-5 are shown in Table 1, and the others are the same as Example 1.

[0042] It should be noted that the content of each impurity element in the aluminum profile of Example 1-3 and the aluminum profile of Comparative Examples 1-5 is not more than 0.05%, and the total content of impurity elements is not more than 0.15%.

[0043] Comparative Example 6: Comparative Example 6 is different from Example 1 in that the homogenization treatment process parameters in Comparative Example 6 are different, and the others are the same as Example 1, and the homogenization treatment process parameters in Comparative Example 6 are that the temperature is 480℃, and the holding time is 9h.

[0044] Comparative Example 7: Comparative Example 7 is different from Example 1 in that the extrusion process parameters in Comparative Example 7 are different, and the others are the same as Example 1, and the extrusion process parameters in Comparative Example 7 are that the extrusion temperature of the aluminum bar is 460℃, the die temperature is 480℃, the extrusion cylinder temperature is 480℃, the extrusion speed is 2.2mm / s, and the profile discharge port temperature is 490℃.

[0045] Comparative Example 8: Comparative Example 8 is different from Example 1 in that the aging process parameters in Comparative Example 8 are different, and the others are the same as Example 1, and the aging process parameters in Comparative Example 8 are that the temperature is 120℃, and the holding time is 8h.

[0046] Comparative Example 9: Comparative Example 9 is the same as Example 1 except that Comparative Example 9 uses conventional on-line water quenching.

[0047] Table 1: Mass percentage composition of Examples 1-3 and Comparative Examples 1-5

[0048] The aluminum profiles prepared in Examples 1-3 and Comparative Examples 1-9 were tested for performance, and the results are shown in Table 2 below.

[0049] Table 2: Performance test results

[0050] From the data analysis in Table 2, it can be seen that by optimizing the composition and composition ratio of the aluminum profile, the aluminum profiles of Examples 1-3 all exhibit high strength (tensile strength ≥ 419 MPa, yield strength ≥ 359 MPa) and good elongation (≥ 13.6%). Compared with Example 1, the composition content changes in Comparative Examples 1-5, the Fe content changes in Comparative Example 1, and excessive Fe content leads to an increase in coarse brittle phases, which seriously damages the toughness. High Fe content and increased brittle phases result in mechanical properties that are not as good as those of Example 1. In Comparative Example 2, the Mn content is low, and the grain refinement effect and Fe phase transformation effect of Mn are weakened, resulting in lower strength than Example 1. In Comparative Example 3, the Mg, Si, and Cu contents are low, and the strength is far from meeting the requirements of high-performance battery trays, indicating that the composition optimization of the present application can significantly change the mechanical properties of the aluminum profile. In Comparative Example 4, the Mg and Si contents are too high, although the mechanical strength is excellent, the elongation at break is reduced. In Comparative Example 5, the high Cu content brings high strength, but seriously sacrifices the corrosion resistance of the material (especially the stress corrosion cracking resistance), which is a fatal defect for battery trays used in complex working conditions. Therefore, the applicant believes that by optimizing the composition and composition ratio, the present application can significantly improve the mechanical properties of the aluminum profile as a whole, and any deviation of the key alloying elements (Mg, Si, Cu, Mn) from the scope of the present application or the excess of impurity elements (Fe) cannot obtain the aluminum profile with excellent comprehensive performance of the present application.

[0051] The insufficient homogenization in Comparative Example 6 leads to uneven composition and structure of the ingot, and the non-equilibrium eutectic phase cannot be completely dissolved, resulting in decreased final strength and structure uniformity, and further affecting the mechanical properties of the profile. In Comparative Example 7, the extrusion temperature is changed, resulting in that the strengthening phase (Mg2Si) cannot be fully solid-solved in the matrix, and the subsequent aging strengthening effect is poor, and the strength is significantly reduced. In Comparative Example 8, the aging process parameters are changed, and the lower under-aging process obtains higher toughness, but the strength is far from the peak value, proving the importance of the aging process of the application in achieving better strength. As can be seen from Comparative Examples 6-8, even if the composition is the same, the deviation of any one of the key process steps (homogenization, extrusion temperature, aging) will lead to a significant decrease in the final performance, and it is impossible to achieve the high strength level achieved by the application. It also shows that the high performance of the aluminum profile of the application is obtained under the precise control of the composition, composition ratio and process. In Comparative Example 9, the conventional online water quenching process is used, and the gas-mist-water online quenching system is not used, resulting in uneven cooling of each part of the profile, and generating certain internal stress. In addition, insufficient cooling strength caused by insufficient water temperature or flow will result in insufficient supersaturation of the solid solution, and the subsequent aging of the strengthening phase will be reduced, resulting in substandard strength of the profile, and the uneven cooling caused by the conventional single water quenching will also affect the consistency of the appearance and performance of the product.

[0052] In addition, Figure 1 The metallographic structure of the profile in Example 1 of the application is shown in the figure. Figure 1 As can be seen from the figure, the profile of the application has a uniform structure.

[0053] In addition, the aluminum bar of the present application shows a grain size of 1-1.5 grade (1.5 grade only in the center of the ingot); the porosity is less than 1 grade; no slag and crack defects are found in the macrostructure, and no bright crystal and feather-like grain structure is found; no slag, obvious scratches and cold shut defects are found in the appearance; no internal cracking is found by ultrasonic flaw detection, and the structure is uniform.

[0054] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0055] The above-described embodiments only express several embodiments of the application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are within the scope of protection of the application. Therefore, the protection scope of the patent of the application should be subject to the appended claims.

Claims

1. A high-performance aluminum profile for a battery tray, characterized in that, The high-performance aluminum profile comprises the following components by mass percentage: Mg 1-1.1%, Si 0.8-0.9%, Mn 0.25-0.30%, Cu 0.7-0.8%, Fe not more than 0.15%, and the balance Al; the content of a single impurity element is not more than 0.05%, and the total content of impurity elements is not more than 0.15%.

2. The high-performance aluminum profile for a battery tray according to claim 1, characterized in that, The high-performance aluminum profile used for the battery tray has a tensile strength ≥419MPa, a yield strength ≥359MPa, and an elongation after fracture ≥13.6%.

3. A method for preparing a high-performance aluminum profile for a battery tray, characterized in that, The preparation method for producing the high-performance aluminum profile for battery trays as described in claim 1 or 2, the preparation method comprising the following steps: S1. Melting and casting: High-purity aluminum ingots, silicon and manganese additives are added to the melting furnace, heated until melted, magnesium ingots are added, and melting is carried out. After all the furnace charge has melted, the melt is stirred thoroughly. S2. In-furnace refining and refining treatment: Add refining agent into the furnace for refining treatment, stir thoroughly, remove slag, let stand for 20-30 minutes, and after confirming that the composition is within the designed range, add refining agent. S3. Casting: The ingot is cast using a semi-continuous, horizontal hot-top casting method. The molten aluminum enters the crystallizer through an inlet plate. The descent speed of the lifting platform is controlled according to the flow rate of the melt and cooling water, gradually forming an aluminum rod during the descent. S4. Online Inspection: The aluminum rod undergoes low-magnification sample inspection. After meeting the requirements, it enters the homogenization process. S5. Extrusion and Online Quenching: The homogenized aluminum rod is heated to 500-520℃. The extrusion temperature of the aluminum rod is 500-520℃, the die temperature is 470-490℃, the extrusion cylinder temperature is 400-450℃, the extrusion speed is 1.5-2.5 mm / s, and the profile outlet temperature is 530-550℃. Online quenching is then performed to cool it to below 50℃ within 1 minute. S6. Artificial Aging: The extruded profile is aged at 170-190℃ for 7-9 hours.

4. The preparation method according to claim 3, characterized in that, In step S1, the melting temperature is 730-760℃.

5. The preparation method according to claim 3, characterized in that, In step S2, the refining process is carried out using a composite rotary jetting process. First, a mixture of argon and chlorine gas is introduced for refining for 10-15 minutes. Then, a refining agent is added, and the refining process continues for 15-20 minutes. After refining, the hydrogen content of the melt is ≤0.10mL / 100gAl, and the inclusion content is ≤5 particles / mm.

6. The preparation method according to claim 5, characterized in that, The refining agent is obtained by mixing sodium chloride and graphite in a mass ratio of (1-5):(5-9); The amount of the refining agent added is 0.1-0.3% of the mass of the melt.

7. The preparation method according to claim 1, characterized in that, The refining agent is Al-5Ti-1B wire; the amount of the refining agent added accounts for 0.02-0.03% of the mass of the melt.

8. The preparation method according to claim 1, characterized in that, In step S3, the casting temperature is 710-720℃, the casting speed is 90-100 mm / min, the cooling water pressure is 0.1-0.2 MPa, and the cooling water temperature is ≤50℃.

9. The preparation method according to claim 3, characterized in that, In step S4, the homogenization treatment temperature is 560-580℃, and the holding time is 8-9h.

10. A battery tray, characterized in that, The battery tray is made from the high-performance aluminum profile described in claim 1 or 2.

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